The present invention relates to a radiation source comprising open cavities, energised by two dipoles which are orthogonal and preferably operating within the microwave range.
This source is usable as a primary energisation source for an optical system of the focussing type or as a radiating element of an antenna array, whether the array is in a linear plane or arranged on an other surface.
Amongst the different known embodiments of radiation sources having an open cavity energised by two orthogonal dipoles, none operates within two different frequency bands. As a matter of fact, they merely radiate two waves simultaneously according to two crossed polarisations or with a circular polarisation within a single frequency band. FIG. 1 illustrates a particular embodiment of such a prior art radiation source described in the review "Microwave Journal" of May 1977, pages 47 to 49, where the open cavity 1 is of the cylindrical type energised by two dipoles 2 and 3 arranged in cruciform fashion and comprising a plane element 4 placed in front of the radiating aperture 5 in order to enhance its directivity.